Wow. That's really good for a first timer! Of course there is room for improvement (as there always is) and practice, but this is a great start.
The only critique I have at the moment is the bottom part of the body. I understand if you were trying to only show the top half, but the cutoff of the jeans/pants is a little... awkward looking. Maybe try making the cut-off more subtle in the future instead of being just a straight line? Just a thought.
I would give this a 9.5/10 (: